Home › Words › T › twirtiestwirtiestwirties means the age range from age 20 through age 39.EtymologyBlend of twenties + thirties.nounThe age range from age 20 through age 39.e.g.“Our Friday evening visit saw a predictable crowd of Magners-swilling, besuited gents being eyed up by glammed-up women in their twirties.” — 2007, Time Out London Bars, Pubs and Clubs, page 150:Definitions & examples from Wiktionary (CC BY-SA 3.0).